Note: The follow are two excerpts from the Wayne State Biomechanical Study of neck braces. The entire report is also available to view. Click the link to the right to view it.
Initial Biomechanical Testing of the L.E.X.BRACE, "Cowboy Collar" and "Roll Collar" at Wayne State University's Biomechanics Lab, Detroit, Michigan.
A summary of results is given in Table 1 indicating the maximum values obtained during the tests.
Table 1: Maximum Value Obtained During Tests
NA = Not a significant measure in particular test [Color added to chart for emphasis]
Device Imp Location Imp Vel (m/s) Axial (N) Extension (N-m) Flexion (N-m) Shear (N) Severity Index Peak Head G None Front 3.48 NA 100 NA 1070 91 20 Roll Front 3.26 NA 50 NA 730 141 18 Collar Front 3.33 NA 89 NA 982 126 18 Lex Front 3.31 NA 88 NA 966 15 15 None 25 ° fr SI 3.47 3000 NA 65 NA 187 17 Lex 25 ° fr SI 3.45 3600 NA 76 NA 23 26
When comparing the shock attenuating properties of the various devices to the no brace condition (Table 1), it can be seen that the L.E.X. BRACE significantly reduced the shock the brain experiences during the impact. While on the other hand, the other two devices appear to increase the severity of the impact as measured by the SI. The changes in SI with the use of a cervical device may play an important factor in the continued effort to reduce the number of concussions that occur in football every year. It is apparent from this data that more research needs to be done on the relationship between cervical spine protection and its effect on head injury.
Cervical Devices have an effect on both the loads seen in the neck region as well as the harshness of the impact as measured by the severity index (SI). In most cases the cervical brace reduced the forces seen in the occipital region as compared to the no brace condition. The reduction in the observed peak forces changed from brace to brace with the neck roll providing the most protection to the upper neck against the hyperextension forces of a frontal impact. In the frontal impacts, shear and axial loading do not seem to be important factors in the injury mechanism since they are well below their respective injury tolerance levels. When examining the effect that a cervical device has on the severity of the impact, the findings are surprising. The use of a cervical device seems to increase the SI value over that when no device is used. The only cervical device that lowered the SI in the frontal impact was the L.E.X. BRACE. The L.E.X. BRACE also reduced the SI value in the axial loading case. The exact mechanism that causes these trends is still unknown and additional research still needs to be conducted.
In conclusion, when looking at any type of protective equipment, its effect on the entire system must be examined. When evaluating the various types of neck protection devices, it is important to determine how they protect the cervical spine from injury as well as their effect on the accelerations that cause head injury. With today's technology we have the capability of tracking both the head and neck's response to a given input.
Wayne State University is continuing its research into making sports safer on the road, on the field and in the ring. If we can be any service in your endeavors please feel free to contact us to discuss the capabilities of our facilities.